NC0089877_Draft Permit_20240723

ROY COOPER
Governor ^. Mt.
ELIZABETH S.BISER w
Secretary
RICHARD E.ROGERS.JR. NORTH CAROLINA
Director Environmental Quality
July 23,2024
Seth Brown
Onslow Water and Sewer Authority
228 Georgetown Road
Jacksonville,NC 28540
Subject: Draft of NPDES Permit NC0089877
Webb Creek WWTP
Onslow County
Class WW-3
Dear Permittee:
The Division has reviewed your request to renew the subject permit. Please review this draft carefully to ensure a
thorough understanding of the information,conditions,and requirements it contains.
This draft contains the following major changes from the existing permit:
• Section A.(7.)has been updated to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports.
• Monitoring for the parameters of Total Kjeldahl Nitrogen and Nitrate plus Nitrite Nitrogen has been
added to Section A.(1.).
• The Waste Load Allocation spreadsheet for this discharge calculated NH3-N limits of 1.0 mg/L for
summer and 1.8 mg/L for winter. However,Division policy has established that for small discharges(< 1
MGD)the best available treatment technology for these facilities leads to monthly average limits no
lower than 2 mg/L- summer and 4 mg/L—winter. The daily maximums for these parameters have been
updated to 5 times the Monthly Average.
• Section A. (5.) status has been updated to active following the submittal of the required Engineer's
Certificate. The allocation table has been updated to include the estuary TN allocation.
With this notification,the Division will solicit public comment on this draft permit by publishing a notice in
newspapers having circulation in the general Onslow County area,per EPA requirements. Please provide your
comments,if any,to me no later than 30 days after receiving this draft permit.
Following the 30-day public comment period,the Division will review all pertinent comments and take
appropriate action prior to issuing a final permit. If you have questions concerning the draft,please contact me via
e-mail at [e-mail] or via phone at 919-707-3600.
Sincerely,
V
Sara Bassett
.-‘ Nora Cara lira Department of Er troy a tal Quality Division of Water Resour:es
D E '/) 512 Nora.Salt'bury Strait 161-Mail Sarvi:a Carter Raleigh,North Carolina 276W-161-
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Environmental Specialist I
NPDES Compliance and Expedited Permitting
cc: NPDES files [Laserfiche]
Wilmington Regional Office [Laserfiche]
Operator Certification Program[Laserfiche]

NPDES Permit NC0089877
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended, the
Onslow Water and Sewer Authority (ONWASA)
is hereby authorized to discharge wastewater from a facility located at the
Webb Creek WWTP
2.50 Zachary Lane
Hubert
Onslow County
to receiving waters designated as Wallace Creek in the White Oak River Basin in accordance with
effluent limits, monitoring requirements, and other conditions set forth in Parts I, II, III, and IV hereof.
This permit shall become effective
This permit and authorization to discharge shall expire at midnight on July 31,2029.
If the permittee intends to continue to discharge at the facility beyond the term of this permit, a renewal
application must be submitted no later than February 1, 2029(180 days before the expiration of this
permit).
Signed this day
John E. Hennessy, Section Chief Regional Operations
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 9

NPDES Permit NC0089877
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge, are hereby
superseded and, as of this issuance, any previously issued permit describing this treatment facility or
bearing this number is no longer effective. Therefore, the exclusive authority to operate and discharge
from this facility arises under the permit conditions, requirements, terms, and provisions described
herein,
ONWASA is hereby authorized to:
1. Operate an existing 0.35 MGD wastewater treatment facility(located at 250 Zachary Lane, Hubert,
Onslow County) at the Webb Creek WWTP, that includes the following components:
• Two(2) 1.87 MGD Rotary Drum Screen System with containment
• One (1) 39,300-gallon Equalization Basin(Pre-Anoxic)
• Two(2) 38,350-gallon Pre-Aeration Basins with air diffusers
• One (1) 32,800-gallon Post-Anoxic Basin with mixer
• Two(2) 20,750-gallon MBR Basins with eight(8)0.04-micron membrane cassettes
• Five(5) Blowers (2 pre-aeration, 3membrane)
• One(1) 38,350-gallon Aerobic Digester with air diffusers
• One (1)Effluent Wash Water Wet Well with two (2) 128 GPM submersible Wash Water
Pumps
• One(1)Effluent Composite Sampler
• One (1)Effluent Lift Station Wet Well with two (2) 1,100 GPM submersible Effluent Pumps
• One (1) 55-gallon Peracetic Acid Tank with containment and dual 280 GPH metering pump
system
• One (1) 55-gallon drum Alum feed system with dual 1.8 GPH metering pumps
• One (1) 55-gallon Micro-C feed system with dual 20 GPH metering pumps
2. Discharge from said treatment works at the location specified on the attached map into Wallace
Creek [Stream Segment: 19-20] [HUC: 030203010301], in subbasin 03-05-02 currently classified
SB-NSW waters in the White Oak River Basin.
Page 2 of 9

NPDES Permit NC0089877
PART I
A. (1.) EFFLUENT LIMITS AND MONITORING REQUIREMENTS
[15A NCAC 02B.0400 et seq.,02B.0500 et seq.]
Grade WW-3 Biological Water Pollution Control System [15A NCAC 08G .0302]
During the period beginning on the effective date of the permit and lasting until expiration, the permittee
is authorized to discharge treated wastewater from outfall 001. Such discharges shall be limited and
monitored' by the permittee as specified below:
EFFLUENT CHARACTERISTICS EFFLUENT LIMITS MONITORING REQUIREMENTS
Parameter Description-eDMR Code Quarterly Monthly Daily Measurement Sample Type Sample
Average Average Maximum Frequency Location2
Flow(MGD) 50050 0.35 Continuous Recorder Influent or
Effluent
BOD,5-Day(20 Deg.C) -Winter* C0310 10.0 15.0 3/week Composite Effluent
(mg/L)
BOD,5-Day(20 Deg.C)—Summer* C0310 5.0 7.5 3/week Composite Effluent
(mg/L)
Total Suspended Solids(mg/L) C0530 30.0 45.0 3/week Composite Effluent
Nitrogen,Ammonia Total(as N) C0610 2.0 10.0 3/week Composite Effluent
Winter*(mg/L) p
Nitrogen,Ammonia Total(as N) C0610 4.0 20.0 3/week Composite Effluent
Summer*(mg/L)
Temperature(Deg.C) 00010 Monitor&Report Daily(5/week) Grab Effluent
Dissolved Oxygen(mg/L) 00300 Daily average>6.0 3/week Grab Effluent
Total Phosphorus(as P)(mg/L) C0665 2.0 Weekly Composite Effluent
Total Nitrogen(as N) (mg/L) C0600 Monitor&Report 2/Month Composite Effluent
TKN(mg/L) 00625 Monitor&Report 2/Month Grab Effluent
NO3-N+NO2-N (mg/L) 00630 Monitor&Report 2/Month Grab Effluent
TN Load 3(Pounds/Month) QM600 Monitor&Report Monthly Calculated Effluent
TN Load 3(Pounds/Year) QY600 5,896 Annually Calculated Effluent
Enterococci,colony forming units 61211 35 276 3/week Grab Effluent
(cfu/100 ml)
pH—00400(s.u.) 00400 >6.8 and<8.5 3/week Grab Effluent
pH—00400(s.u.) 00400 Monitor&Report Weekly Grab Upstream&
Downstream
Temperature(Deg. C) 00010 Monitor&Report Weekly Grab Upstream&
Downstream
Dissolved Oxygen(mg/L) 00300 Monitor&Report Weekly Grab Upstream&
Downstream
*Winter: November 1 -March 31 Summer: April 1 -October 31
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NPDES Permit NC0089877
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the Division's eDMR system
[see A. (7.)].
2. Upstream=at least 100 feet upstream from the outfall. Downstream=at the nearest road.
3. TN load is the mass quantity of total nitrogen discharged in a given time period. See condition A. (4)of
this permit.
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN
TRACE AMOUNTS.
Page 4 of 9

NPDES Permit NC0089877
A. (2.) NUTRIENT CONDITION FOR PERMITS WITH PHOSPHOROUS LIMITS
[15A NCAC 02B .0223]
This permit may be modified or revoked and reissued to change the existing effluent limits for nutrients
if:
1. Findings by the Division determine nutrient control is necessary
2. Local actions do not successfully reduce the nutrient loading to the receiving stream
3. Nutrient-based problems appear in the receiving stream
A. (3.) CALCULATION OF TOTAL NITROGEN LOADS
[G.S. 143-215.1(B)]
a. The Permittee shall calculate monthly and annual TN Loads as follows:
i. Monthly TN Load (pounds/month)=TN x TMF x 8.34
where:
TN = the average Total Nitrogen concentration (mg/L) of the composite
samples collected during the month
TMF = the Total Monthly Flow of wastewater discharged during the month
(MG/month)
8.34 = conversion factor, from (mg/L x MG) to pounds
ii. Annual TN Load (pounds/year) = Sum of the 12 Monthly TN Loads for the calendar year
b. The Permittee shall report monthly Total Nitrogen results (mg/L and pounds/month) in the
discharge monitoring report for that month and shall report each year's annual results
(pounds/year) in the December report for that year.
A. (4.) ANNUAL LIMITS FOR TOTAL NITROGEN
[G.S. 143-215.1(B)]
a. Total Nitrogen (TN) allocations and TN Load limits for NPDES dischargers apply on a calendar
year basis.
b. For any given calendar year, the Permittee shall be in compliance with the annual TN Load limit in
this Permit if:
(i.) the Permittee's annual TN discharge is less than or equal to its TN Load limit, or
(ii.) the Permittee is a co-permittee member of a compliance association.
c. The TN Load limit in this Permit (if any) may be modified as the result of allowable changes in the
Permittee's TN allocation.
i. Allowable changes include those resulting from purchase of TN allocation from the Wetlands
Restoration Fund; purchase, sale, trade, or lease of allocation between the Permittee and other
dischargers; regionalization; and other transactions approved by the Division.
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NPDES Permit NC0089877
ii. The Permittee may request a modification of the TN Load limit in this Permit to reflect
allowable changes in its TN allocation. Upon receipt of timely and proper application, the
Division will modify the permit as appropriate and in accordance with state and federal
program requirements.
iii. Changes in TN limits become effective on January 1 of the year following permit
modification. The Division must receive application no later than August 31 for changes
proposed for the following calendar year.
iv. Application shall be sent to:
NCDWR/NPDES Program
Attn: White Oak River Basin Coordinator
1617 Mail Service Center
Raleigh,NC 27699-1617
d. If the Permittee is a member and co-permittee of an approved compliance association, its TN
discharge during that year is governed by that association's group NPDES permit and the TN limits
therein.
i. The Permittee shall be considered a Co-Permittee Member for any given calendar year in
which it is identified as such in Appendix A of the association's group NPDES permit.
ii. Association roster(s) and members' TN allocations will be updated annually and in accordance
with state and federal program requirements.
iii. If the Permittee intends to join or leave a compliance association, the Division must be
notified of the proposed action in accordance with the procedures defined in the association's
NPDES permit.
(A) Upon receipt of timely and proper notification,the Division will modify the permit as
appropriate and in accordance with state and federal program requirements.
(B) Membership changes in a compliance association become effective on January 1 of the
year following modification of the association's permit.
e. The TN monitoring and reporting requirements in this Permit remain in effect until expiration of
this Permit and are not affected by the Permittee's membership in a compliance association.
A. (5.) TOTAL NITROGEN ALLOCATIONS
[G.S. 143-215.1]
a. The following table lists the Total Nitrogen(TN)allocation(s)assigned to, acquired by, or
transferred to the Permittee in accordance with North Carolina GS 143-215.1 and the status of each
as of permit issuance. For compliance purposes,this table does not supersede any TN limit(s)
established elsewhere in this permit or in the NPDES permit of a compliance association of which
the Permittee is a Co-Permittee Member.
ALLOCATION AMOUNT a► STATUS
ALLOCATION TYPE SOURCE
Discharge Estuary
(pounds/year) (pounds/year)
Base Assigned by Rule 5,896 2,948 Active
(GS 143-215.1)
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NPDES Permit NC0089877
Footnote:
(1) Transport Factor=50%
Any addition, deletion, or modification of the listed allocation(s) (other than to correct typographical
errors) or any change to Active status of any of the listed allocations shall be considered a major
modification of this permit and shall be subject to the public review process afforded such modifications
under state and federal rules.
A. (6.) TEMPORARY MEANS OF DISINFECTION
In the event that the wastewater treatment plant's membrane bioreactor (MBR) system should fail,
underperform, or otherwise be removed from effective service, the permittee or his agent should
immediately inform the Surface Water Protection Staff of the Wilmington Regional Office of this
development and notify them of use of temporary, alternate means for disinfection of the effluent.
A. (7.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(B)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and program
reports. The final NPDES Electronic Reporting Rule was adopted and became effective on December
21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit (Standard Conditions for NPDES Permits):
• Section B.(11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E.(5.) Monitoring Reports
1. Reporting Requirements [Supersedes Section D. (2.)and Section E.(5.)(a)l
The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic
Discharge Monitoring Report(eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. The eDMR system may be
accessed at: https://deq.nc.gov/about/divisions/water-resources/edmr.
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband
access, then a temporary waiver from the NPDES electronic reporting requirements may be granted
and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3)or
alternative forms approved by the Director. Duplicate signed copies shall be submitted to the
following address:
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NPDES Permit NC0089877
NC DEQ/Division of Water Resources/Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh,North Carolina 27699-1617
See "How to Request a Waiver from Electronic Reporting" section below.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
reported via the eDMR system no later than the last calendar day of the month following the
completed reporting period. Regardless of the submission method, the first DMR is due on the last
day of the month following the issuance of the permit or in the case of a new facility, on the last day
of the month following the commencement of discharge.
Starting on December 21, 2025, the permittee must electronically report the following compliance
monitoring data and reports, when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports; and
• Clean Water Act(CWA) Section 316(b)Annual Reports.
The permittee may seek an electronic reporting waiver from the Division (see"How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9), the permittee must identify the initial recipient at the time
of each electronic submission. The permittee should use the EPA's website resources to identify the
initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity
(EPA or the state authorized by EPA to implement the NPDES program) that is the designated entity
for receiving electronic NPDES data [see 40 CFR 127.2 (b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and for each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at: https://www.federalregister.gov/documents/2015/10/22/2015-
24954/national pollutant-discharge-elimination-system-npdes-electronic-reporting-rule
Electronic submissions must start by the dates listed in the "Reporting Requirements" section above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to
the Division. Requests for temporary electronic reporting waivers must be submitted in writing to
the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring data
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NPDES Permit NC0089877
and reports shall be submitted electronically to the Division unless the permittee re-applies for and is
granted a new temporary electronic reporting waiver by the Division. Approved electronic reporting
waivers are not transferrable. Only permittees with an approved reporting waiver request may
submit monitoring data and reports on paper to the Division for the period that the approved
reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page:
http://deq.nc.gov/aboutidivisions/water-resources/edinr
4. Signatory Requirements [Supplements Section B. (11.)(b)and Supersedes Section B.(11.)(d)l.
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II,
Section B. (11.) (a) or by a duly authorized representative of that person as described in Part II,
Section B. (11.) (b). A person, and not a position, must be delegated signatory authority for eDMR
reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall make
the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION
WILL BE ACCEPTED:
"I certify, wider penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the information,
the information submitted is, to the best of my knowledge and belief true, accurate, and complete. I
am aware that there are significant penalties,for submitting false information, including the
possibility of fines and imprisonment for knowing violations."
5. Records Retention [Supplements Section D. (6.)1
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from the
date of the report. This period may be extended by request of the Director at any time [40 CFR
122.41].
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